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                                                                     EXHIBIT 4.2
                             SUPPLEMENTAL INDENTURE

      THIS SUPPLEMENTAL INDENTURE (the "SUPPLEMENTAL INDENTURE") is made as of
the 28th day of May 2004, among First Capital Bancorp, Inc., a Georgia
corporation ("FIRST CAPITAL" or the "COMPANY"), as original issuer; CNB
Holdings, Inc., a Georgia corporation (the "SUCCESSOR COMPANY"); and U.S. Bank
National Association, as trustee (the "TRUSTEE").

      WHEREAS, the Company and the Trustee have entered into an Indenture, dated
as of January 17, 2002 (the "ORIGINAL INDENTURE"), pursuant to which the Company
issued its 9.0% Subordinated Debentures due January 15, 2032 (the "DEBENTURES")
in an aggregate principal amount of $6,392,000; and

      WHEREAS, the Company intends to merge with and into the Successor Company
pursuant to the Agreement and Plan of Merger, dated as of September 24, 2003 and
amended as of March 8, 2004, with the Successor Company being the sole surviving
entity (the "MERGER") (the effective time and date of the Merger is referred to
herein as the "MERGER DATE"); and

      WHEREAS, effective as of the Merger Date, the Successor Company is to
assume the due and punctual payment of the principal of and interest on all of
the Debentures and the due and punctual performance and observance of covenants
and conditions of the Original Indenture on the part of First Capital to be
performed or observed; and

      WHEREAS, pursuant to Section 12.1 of the Original Indenture, the Company
and the Trustee are required to amend or supplement the Original Indenture to
evidence the merger of the Company into the Successor Company in accordance with
and subject to the terms and conditions of the Original Indenture and the
Debentures; and

      WHEREAS, this Supplemental Indenture has been duly authorized by all
necessary corporate action on the part of the Company and the Successor Company.

      NOW, THEREFORE, the Company, the Successor Company and the Trustee agree
as follows for the equal and ratable benefit of the holders of the Debentures:

                                    ARTICLE I
                                   DEFINITIONS

      SECTION 1.01 Definitions.

            (a)   For purposes of this Supplemental Indenture, terms used but
not defined herein except as otherwise expressly provided or unless the context
otherwise requires have the meanings assigned to them in the Original Indenture.

            (b)   "Indenture" means the Original Indenture, as amended by this
Supplemental Indenture or as otherwise supplemented or amended from time to time
by one or more indentures supplemental thereto or hereto entered into pursuant
to the applicable provisions of the Indenture.

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                                   ARTICLE II
                                 THE ASSUMPTION

      SECTION 2.01 Assumption by the Successor Company. Effective as of the
Merger Date, (a) the Successor Company, as a result of its being the surviving
entity in the Merger, agrees that, pursuant to Section 12.1 of the Original
Indenture, the due and punctual payment of the principal of and interest on all
of the Debentures, according to their tenor, and the due and punctual
performance and observance of all of the covenants and conditions of the
Indenture to be kept or performed by the Company shall be assumed by the
Successor Company; and (b) pursuant to Section 12.2 of the Original Indenture,
with regard to the Indenture, the Successor Company shall succeed to and be
substituted for the Company, with the same effect as if it had been named in the
Indenture as the party of the first part, and the Company thereupon shall be
relieved of all obligations and covenants under the Indenture or upon the
Debentures. Following the execution and delivery of this Supplemental Indenture,
the parties hereto agree that all references to the "Company" in the Indenture
and the Debentures shall be deemed references to the Successor Company.

                                   ARTICLE III
                                  MISCELLANEOUS

      SECTION 3.01 Effect of Supplemental Indenture. Upon the execution and
delivery of this Supplemental Indenture by the Company, the Successor Company
and the Trustee, the Indenture shall be supplemented in accordance herewith, and
this Supplemental Indenture shall form a part of the Indenture for all purposes,
and every holder of Debentures heretofore or hereafter authenticated and
delivered under the Indenture shall be bound thereby.

      SECTION 3.02 Original Indenture Remains in Full Force and Effect. Except
as supplemented hereby, all provisions in the Original Indenture shall remain in
full force and effect.

      SECTION 3.03 Original Indenture and Supplemental Indenture Construed
Together. This Supplemental Indenture is an indenture supplemental to and in
implementation of the Original Indenture, and the Original Indenture and this
Supplemental Indenture shall henceforth be read and construed together.

      SECTION 3.04 Conflict with Trust Indenture Act. If and to the extent any
provision of this Supplemental Indenture limits, qualifies or conflicts with any
provision of the Trust Indenture Act that is required under the Trust Indenture
Act to be part of and govern any provision of this Supplemental Indenture, the
provision of the Trust Indenture Act shall control. If any provision of this
Supplemental Indenture modifies or excludes any provision of the Trust Indenture
Act that may be so modified or excluded, the provision of the Trust Indenture
Act shall be deemed to apply to the Indenture as so modified or to be excluded
by this Supplemental Indenture, as the case may be.

      SECTION 3.05 Severability. In case any provision in this Supplemental
Indenture shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

      SECTION 3.06 Headings. The Article and Section headings of this
Supplemental Indenture have been inserted for convenience of reference only, are
not to be considered a part of this Supplemental Indenture and shall in no way
modify or restrict any of the terms or provisions hereof.

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      SECTION 3.07 Benefits of Supplemental Indenture, etc. Nothing in this
Supplemental Indenture or the Debentures, express or implied, shall give to any
Person, other than the parties hereto and thereto and their successors hereunder
and thereunder and the Debentureholders, any benefit of any legal or equitable
right, remedy or claim under the Indenture, this Supplemental Indenture or the
Debentures.

      SECTION 3.08 Successors. All agreements of the Company and the Successor
Company in this Supplemental Indenture shall bind its successors. All agreements
of the Trustee in this Supplemental Indenture shall bind its successors.

      SECTION 3.09 GOVERNING LAW. THE INTERNAL LAW OF THE STATE OF GEORGIA SHALL
GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE.

      SECTION 3.10 Notices. Effective as of the Merger Date, the addresses for
notices set forth in the Original Indenture shall be amended, without further
action, to read as follows:

            (a)   if to the Company or the Successor Company:

                  CNB Holdings, Inc.
                  7855 North Point Parkway, Suite 200
                  Alpharetta, Georgia  30022-4849

            (b)   if to the Trustee:

                  U.S. Bank National Association
                  225 Asylum Street
                  Goodwin Square
                  Hartford, Connecticut  06103
                  Attn:  Vice President, Corporate Trust Department

                  with a copy to:

                  U.S. Bank National Association
                  P.O. Box 778
                  Boston,Massachusetts 02110
                  Attn:  Earl W. Dennison, Jr., Corporate Trust Department

      SECTION 3.11 Counterparts. This Supplemental Indenture may be executed in
two or more counterparts, each of which shall constitute an original, but all of
which when taken together shall constitute but one agreement.

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      IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental
Indenture to be duly executed by their duly authorized officers, all as of the
date first written above.

                                    FIRST CAPITAL BANCORP, INC.

                                    By: /s/ William R. Blanton
                                        --------------------------------
                                    Name: William R. Blanton
                                    Title: President and Chief Executive Officer

                                    CNB HOLDINGS, INC.

                                    By: /s/ H.N. Padget, Jr
                                        --------------------------------
                                    Name: H.N. Padget, Jr.
                                    Title: President and Chief Executive Officer

                                    U.S. BANK NATIONAL ASSOCIATION, as Trustee

                                    By: /s/ Earl W. Dennison, Jr.
                                        --------------------------------
                                    Name: Earl W. Dennison, Jr.
                                    Title: Vice President

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